Radial configuration for heat exchanger core

ABSTRACT

A heat exchanger includes a first set of fins, a second set of fins, and an exterior wall. The first set of fins extend radially and are coaxial with each other. The first set of fins forms a first set of channels. The second set of fins extend radially and are coaxial with each other. The second set of fins forms a second set of channels. Channels of the first and second sets of channels are disposed in an alternating pattern in a circumferential direction of the heat exchanger. The first and second sets of fins are integrally formed together. A cross-sectional width of a channel of at least one of the first set of channels and the second set of channels increases as a radial distance from a centerline axis of the heat exchanger increases.

BACKGROUND

The present disclosure relates to heat exchangers. More particularly,the present disclosure relates to an additively manufactured heatexchanger.

The practical limitations of traditional manufacturing methods createlimited geometry, shape, and arrangement of internal features incomponents such as heat exchangers. These limitations can constrainthermal energy transfer and fluid flow performance in the heatexchanger. Moreover, the ability to handle high pressures, temperatures,and their associated transient conditions can be diminished as well.

SUMMARY

A heat exchanger includes a first set of fins, a second set of fins, andan exterior wall. The first set of fins extend radially and are coaxialwith each other. The first set of fins forms a first set of channels.The second set of fins extend radially and are coaxial with each other.The second set of fins forms a second set of channels. Channels of thefirst and second sets of channels are disposed in an alternating patternin a circumferential direction of the heat exchanger. The first andsecond sets of fins are integrally formed together. A cross-sectionalwidth of a channel of at least one of the first set of channels and thesecond set of channels increases as a radial distance from a centerlineaxis of the heat exchanger increases.

A method of manufacturing a heat exchanger includes forming a first anda second set of fins via layer-by-layer additive manufacturing. Thefirst set of fins extend radially, are coaxial with each other, and forma first set of channels. A second set of fins extends radially and arecoaxial with each other. The second set of fins forms a second set ofchannels. The channels of the first and second sets of channels aredisposed in an alternating pattern in a circumferential direction. Thefirst and second sets of fins are integrally formed together. Across-sectional width of a channel of at least one of the first set ofchannels and the second set of channels increases as a radial distancefrom a centerline axis of the heat exchanger increases. A curvedexterior wall is formed with layer-by-layer additive manufacturing andsuch that the curved exterior wall is integrally formed to the first andsecond sets of fins. The first and second sets of fins are containedwithin the exterior wall.

The present summary is provided only by way of example, and notlimitation. Other aspects of the present disclosure will be appreciatedin view of the entirety of the present disclosure, including the entiretext, claims, and accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heat exchanger with mounting armsconnected to a central spar.

FIG. 2 is a cross-section view of the heat exchanger taken along 2-2shown in FIG. 1 .

FIG. 3 is an isolated view of the central spar and the mounting arms.

FIG. 4A is an enlarged view of the central spar with a plurality ofrings.

FIG. 4B is an isolation view of a tab of a ring of the central spar.

FIG. 5 is a supplementary cross-section view of a portion of the heatexchanger.

FIG. 6A is a perspective isolation side-by-side view of opposite ends ofa first fin circuit of the heat exchanger core.

FIG. 6B is a perspective isolation side-by-side view of opposite ends ofa second fin circuit of the heat exchanger core.

FIG. 6C is a perspective isolation side-by-side view of opposite ends ofthe first and second fin circuits combined together with a third header.

FIG. 6D is a perspective isolation side-by-side view of opposite ends ofthe first and second fin circuits combined together with the first and asecond header.

FIG. 7A is a cross-section view of a first header fin arrangement.

FIG. 7B is a cross-section view of a second header fin arrangement.

FIG. 8 is a supplementary cross-section view of a portion of the heatexchanger.

FIG. 9 is a perspective isolated view of a set of fins of a core of theheat exchanger.

While the above-identified figures set forth one or more embodiments ofthe present disclosure, other embodiments are also contemplated, asnoted in the discussion. In all cases, this disclosure presents theinvention by way of representation and not limitation. It should beunderstood that numerous other modifications and embodiments can bedevised by those skilled in the art, which fall within the scope andspirit of the principles of the invention. The figures may not be drawnto scale, and applications and embodiments of the present invention mayinclude features and components not specifically shown in the drawings.

DETAILED DESCRIPTION

This disclosure presents a heat exchanger core with a round/curvedexterior and radial fluid channels with varying cross-sectional widths.This geometry increases the overall thermal energy transfer and pressuredrop efficiency of the core while decreasing the total volume of theheat exchanger.

FIG. 1 is a perspective view of heat exchanger 10, which includes body12 (with exterior skin 14), central spar 16 (extending along centerlineaxis A_(CL)), mounting arms 18, and external mount 20.

Heat exchanger 10 is a device for transferring thermal energy betweentwo or more fluids. In this example, heat exchanger 10 is a heatexchanger used in an aircraft. Also in this example, heat exchanger 10and all of its components are built as a single, monolithic piece ofmaterial via layer-by-layer additive manufacturing. In this non-limitingembodiment, a type of additive manufacturing used to build heatexchanger 10 can include a powder bed fusion process such as selectivelaser sintering, direct metal laser sintering, and/or electron beammelting.

Body 12 is a main portion of heat exchanger 10. In this example, body 12includes a cylindrical shape with curved or rounded ends. In thisexample, body 12 contains a heat exchanger core with fins (not shown inFIG. 1 ; see e.g., FIG. 2 ). Exterior skin 14 is an external surface ofbody 12. Central spar 16 is a cylindrical piece of solid material.Mounting arms 18 are elongate extensions of solid material. In thisnon-limiting embodiment, mounting arms 18 include an oval or ellipticalcross-section shape. Additionally, mounting arms 18 can include astraight or wavy configuration as shown in FIG. 1 (see e.g., FIG. 3 ).External mount 20 is a band or ribbon or solid material. Centerline axisA_(CL) is a central axis of body 12 and of heat exchanger 10.

Heat exchanger 10 and all of its components (e.g., body 12, exteriorskin 14, central spar 16, mounting arms 18, and/or external mount 20)are integrally formed together as a single, monolithic piece of materialvia layer-by-layer additive manufacturing. Body 12 is connected toexternal mounting surfaces (not shown in FIG. 1 ). For example, body 12can be connected to an engine or an engine housing via mounting arms 18and/or external mount 20. Exterior skin 14 defines an exterior of body12. Central spar 16 is disposed in the center of body 12. In thisexample, central spar 16 is disposed coaxially with centerline axisA_(CL) of body 12. In other words, central spar 16 is coaxial withcenterline axis A_(CL) of body 12.

Mounting arms 18 are connected to and extend radially from central spar16. In this example, mounting arms 18 connect to central spar 16 at thelongitudinal ends of central spar 16. Mounting arms 18 are integrallyformed with central spar 16 via layer-by-layer additive manufacturing.Also in this example, distal ends of mounting arms 18 can connected tothe engine or the engine housing of the aircraft. In this non-limitingembodiment, a major axis of mounting arms 18 can be perpendicular (e.g.,orthogonal) to centerline axis A_(CL) of heat exchanger 10. Externalmount 20 is formed with, is connected to, and extends radially outwardfrom exterior skin 14. In this example, external mount 20 is integrallyformed with exterior skin 14 via layer-by-layer additive manufacturing.

Heat exchanger 10 transfers thermal energy between two or more fluids.For example, heat exchanger 10 utilizes multiple fin arrays containedwithin body 12 to direct multiple flows of fluid across the fins inorder to transfer thermal energy from a first fluid, to the fins, and toa second fluid. Exterior skin 14 provides structural support forinternal fin arrays disposed within body 12. Exterior skin 14 alsoprovides a fluidic barrier that guides fluid through body 12 and preventfluid from escaping out of body 12 in locations other than designatedinlets and outlets of body 12. Central spar 16 is a central mountingpoint to which mounting arms 18 connect to. In one example, central spar16 transfers loads (e.g., vibrational, thermo-dynamic, etc.) frommounting arms 18 to body 12 of heat exchanger 10. In another example,central spar 16 transfers loads (e.g., vibrational, thermo-dynamic,etc.) from body 12 to mounting arms 18 and on to the external mountingsurfaces mounting arms 18 are mounted to.

Mounting arms 18 mount and connect heat exchanger 10 to an externalmounting surface or surfaces (e.g., within an aircraft). Mounting arms18 also transfer loads (e.g., vibrational, thermo-dynamic, etc.) to/fromcentral spar 16 from/to external mounting surfaces to which mountingarms 18 are attached.

External mount 20 provides an additional mounting location for body 12to attach to an external mounting surface. As will be discussed withrespect to subsequent figures, incorporation of central spar 16 enablesthe heat exchanger core to mount to central spar 16 which allows theheat exchanger core to grow in length and diameter. Additionally, asthermal, vibratory, and/or pressure loads are applied across heatexchanger 10, strain at the connection points between heat exchanger 10and the external structure to which it is mounted via mounting arms 18are significantly reduced. In addition, central spar 16 is designed withadditional compliance to further reduce strain at the connectionsbetween heat exchanger 10 via mounting arms 18 and the externalstructure.

FIG. 2 is a cross-section view of heat exchanger 10 taken along 2-2shown in FIG. 1 and shows body 12, exterior skin 14, central spar 16,mounting arms 18, external mount 20, heat exchanger core 22, externalmounting surfaces 24, connection region 26, and centerline axis A_(CL).

Here, centerline axis A_(CL) is shown as also being a longitudinal axisof central spar 16. Heat exchanger core 22 is an array of fins andfluidic channels. For example, heat exchanger core 22 includes aplurality of radially extending plate fins that form fluidic channelstherebetween. In another example, heat exchanger core 22 can include astacked plate fin type core with a non-radial configuration such as acuboid or other type of polyhedron. External mounting surfaces 24 aresurfaces of a component external to heat exchanger 10 to which mountingarms 18A and 18B are mounted to. In this example, external mountingsurfaces 24 can be a surface of an engine or an engine housing in anaircraft. Connection region 26 is a region of connection points betweencentral spar 16 and heat exchanger core 22.

Central spar 16 is disposed in a center of heat exchanger core 22. Inthis example, central spar 16 is disposed coaxially with centerline axisA_(CL) of heat exchanger core 22. In other words, central spar 16 iscoaxial with centerline axis A_(CL) of heat exchanger core 22. Inanother non-limiting embodiment where heat exchanger core 22 includes apolyhedral shape, central spar 16 can be disposed along a middle/centerof heat exchanger core 22, where the channels and fins of heat exchangercore 22 can be flat and polygonal shaped. Heat exchanger core 22 isdisposed within exterior skin 14 of body 12. For example, heat exchangercore 22 occupies an internal space formed by exterior skin 14. Heatexchanger core 22 is connected to and integrally formed with centralspar 16 via connection region 26. Mounting arms 18A and 18B are mountedor affixed to external mounting surfaces 24. In this example, externalmounting surfaces include receptacles for receiving ends of mountingarms 18A and 18B. Connection region 26 is integrally formed with,connected to, and extends radially between central spar 16 and heatexchanger core 22.

Heat exchanger core 22 transfers thermal energy between two or morefluids. For example, heat exchanger core 22 utilizes multiple fin arrayscontained within body 12 to direct multiple flows of fluid across thefins in order to transfer thermal energy from a first fluid, to thefins, and to a second fluid. In this example, heat exchanger core 22 isconfigured to thermally expand in the axial and radial directionsrelative to centerline axis A_(CL). For instance, as central spar 16expands and contracts in response to thermal expansion, heat exchangercore 22 and connection region 26 expand or contract with central spar16. External mounting surfaces 24 serve as mounting points to whichmounting arms 18A and 18B connect.

Connection region 26 connects heat exchanger core 22 to central spar 16.Connection region 26 includes a flexibility allowing for heat exchangercore 22 to expand and contract in both axial and radial directions ascentral spar 16 grows and contracts due to thermal expansion. Likewise,the flexibility of connection region 26 also allows for central spar 16to expand and contract in both axial and radial directions as heatexchanger core 22 grows and contracts due to thermal expansion.

As heat exchanger core 22 expands with central spar 16 and withconnection region 26, the points of connection between central spar 16,connection region 26, and heat exchanger core 22 experience decreasedamounts of stress and strain as compared to connection points inexisting configurations of heat exchangers without additivelymanufactured components such as central spar 16 and connection region 26that are able to expand and contract with each other in the axial andradial directions.

FIG. 3 is an isolated view of central spar 16 and mounting arms 18A and18B and shows mounting arm 18A (with straight portion 28A, wavy portion30A, major axis 32A, minor axis 34A, proximal end 36A, midpoint 38A, anddistal end 40A), mounting arm 18B (with minor axis 34B, proximal end36B, midpoint 38B, and distal end 40B), and connection region 26 (withsupport members 44).

Mounting arm 18A is a wavy, curved piece of solid material with anelliptical or oval cross-section shape. Straight portion 28A and wavyportion 30A are first and second portions of mounting arm 18A. Majoraxis 32A is one of two axes defining the elliptical cross-section shapeof mounting arm 18A. Minor axis 34A is the second of two axes definingthe elliptical cross-section shape of mounting arm 18A. Proximal end 36Ais an end of mounting arm 18A closest to central spar 16. Midpoint 38Ais a midpoint of a length of mounting arm 18A. Distal end 40A is an endof mounting arm 18A furthest from central spar 16. Mounting arm 18B is astraight, elongate piece of solid material also with an elliptical oroval cross-section shape.

Major axis 32B is one of two axes defining the elliptical cross-sectionshape of mounting arm 18B. Minor axis 34B is the second of two axesdefining the elliptical cross-section shape of mounting arm 18B.Proximal end 36B is an end of mounting arm 18B closest to central spar16. Midpoint 38B is a midpoint of a length of mounting arm 18B. Distalend 40B is an end of mounting arm 18B furthest from central spar 16.Connection region 26 is an annular region containing support members 44.Support members 44 are a plurality of rings or annular disks. In othernon-limiting embodiments, support members 44 can include a round orspring shape

In the illustrated example, mounting arm 18A includes straight portion28A connected to central spar 16 and wavy portion 30A connected tostraight portion 28A. In other non-limiting embodiment, wavy portion 30Acan be directly connected to central spar 16 with straight portion 28Aconnected to an end of wavy portion 30A. In this example, major axis 32Ais displayed at distal end 40A of mounting arm 18A. Here, major axis 32Ais shown as perpendicular, or orthogonal, to centerline axis A_(CL) ofcentral spar 16. In other non-limiting embodiments, major axis 32A ofmounting arm 18A at distal end 40A can be parallel to centerline axisA_(CL) as well as non-parallel and non-orthogonal to centerline axisA_(CL).

In at least one illustrated example, minor axis 34A is displayed atdistal end 40A of mounting arm 18A. Here, minor axis 34A is shown asparallel to centerline axis A_(CL) of central spar 16. In othernon-limiting embodiments, minor axis 34A of mounting arm 18A at distalend 40A can be perpendicular, or orthogonal, to centerline axis A_(CL)as well as non-parallel and non-orthogonal to centerline axis A_(CL).Proximal end 36A of mounting arm 18 is connected to central spar 16. Inthis example, distal end 40A is connected to external mounting surface24 (see e.g., FIG. 2 ). Mounting arm 18B is connected to central spar 16at proximal end 36A.

In this example, major axis 32B is displayed at distal end 40B ofmounting arm 18B. Here, major axis 32B is shown as perpendicular, ororthogonal, to centerline axis A_(CL) of central spar 16. In othernon-limiting embodiments, major axis 32B of mounting arm 18B at distalend 40B can be parallel to centerline axis A_(CL) as well asnon-parallel and non-orthogonal to centerline axis A_(CL). In thisexample, minor axis 34B is displayed at distal end 40B of mounting arm18B. Here, minor axis 34B is shown as parallel to centerline axis A_(CL)of central spar 16. In other non-limiting embodiments, minor axis 34B ofmounting arm 18B at distal end 40B can be perpendicular, or orthogonal,to centerline axis A_(CL) as well as non-parallel and non-orthogonal tocenterline axis A_(CL).

Proximal end 36B of mounting arm 18B is connected to central spar 16. Inthis example, distal end 40B is connected to one of external mountingsurfaces 24. Connection region 26 is disposed radially between centralspar 16 and heat exchanger core 22 (omitted from FIG. 3 for clarity). Inthis example, heat exchanger core 22 is formed with and connected toradially outer ends of support members 44. Support members 44 areintegrally formed with and extend radially outward from central spar 16.In this example, support members 44 are integrally formed with centralspar 16 via layer-by-layer additive manufacturing.

During operation of heat exchanger 10, thermal dynamic loads and deltasare applied to and across central spar 16. As these thermal dynamicloads and deltas are applied to and across central spar 16, central spar16 expands and contracts due to thermal expansion of a material ofcentral spar 16. Due to the cylindrical configuration of central spar16, as central spar 16 absorbs thermal energy, central spar 16 expandsboth radially and axially along centerline axis A_(CL). As central spar16 expands axially along centerline axis A_(CL), the connection pointsof mounting arms 18A and 18B to central spar 16 also move axiallyoutward. Due to the elliptical cross-section shapes of mounting arms 18Aand 18B, mounting arms 18A and 18B bend and flex to allow the thermalgrowth of central spar 16 while reducing strain and stress a theconnection points of mounting arms 18A and 18B with external mountingsurfaces.

Wavy portion 30A enables mounting arm 18A to more easily bend along wavyportion 30A due to its preformed curvature. This preformed curvature isbiased to bend more easily than a straight portion of material (such asin comparison to straight portion 28A or in comparison to mounting arm18B). The elliptical shapes of mounting arms 18A and 18B allow forhigher degrees of bending along the directions of minor axes 34A and 34Bin comparison to bending along the directions of major axes 32A and 32B.In this example, major axes 32A and 32B are oriented perpendicular tocenterline axis A_(CL) at distal ends 34A and 34B. Due to thisperpendicular alignment of major axes 32A and 32B of mounting arms 18Aand 18B at distal ends 34A and 34B, mounting arms 18A and 18B are ableto bend and flex parallel to centerline axis A_(CL) thereby allowing forthermal expansion of central spar 16 without placing undue strain andstress at the point of connection between mounting arms 18A and 18B andthe external mounting surfaces.

As can be seen in FIG. 3 , major axes 32A and 32B and minor axes 34A and34B can vary their orientations relative to centerline axis A_(CL) as afunction of distance from central spar 16. For example, FIG. 3 showsmounting arm 18B as having major axis 32B perpendicular to centerlineaxis A_(CL) and minor axis 34B as being parallel to centerline axisA_(CL) at distal end 40B. In contrast, at the location of proximal end36B, mounting arm 18B includes a minor axis that is perpendicular tocenterline axis A_(CL) and a major axis that is parallel to centerlineaxis A_(CL). These orientations can be adjusted along a length ofmounting arm 18B (and mounting arm 18A) in order to customize a degreeof flex or bendability along each of mounting arms 18A and 18B.

Support members 44 of connection region 26 bend, compress, and expand ascentral spar 16 and heat exchanger core 22 expand and contract due tothermal growth. In this example, support members 44 include compliantdisks with a series of tabs (see e.g., FIGS. 4A and 4B) including curvedportions allowing for flexing in both the radial and axial directionsrelative to central spar 16.

Without mounting arms 18A and 18B being able to bend and flex inresponse to the axial growth of central spar 16, the stress and strainat the connection points of mounting arms 18A and 18B at both centralspar 16 and the external mounting surfaces could cause damage or failureat those connection points during instances of extreme thermal orvibratory loads.

Heat exchanger 10 with central spar 16 and mounting arms 18A and 18Bprovides a connection between central spar 16 and heat exchanger core 22via structural members (support members 44) incorporating compliance inspecific axes/directions. In addition, with mounting arms 18A and 18Bbeing integrally joined to central spar 16, compliance in a specificaxis (such as in an axial direction relative to centerline axis A_(CL)).These features provide the benefits of a reduction in loading at themounting interface of heat exchanger 10 allowing elimination orreduction in size or use of bearings used existing configurations toallow displacement at the connections between the heat exchanger andmounting structure, reduced part count, reduced overall system weight,and improved thermal capability of heat exchanger 10.

FIG. 4A is an enlarged view of central spar 16 and shows a portion ofmounting arm 18B, connection region 26, support members 44 (with tabs46), and shaft 42 of central spar 16. FIG. 4B is an isolation view of asingle tab 46 with inner portion 50, middle portion 52, and outerportion 54. FIGS. 4A and 4B will be discussed in tandem.

Each of support members 44 include a plurality of tabs 46. Tabs 46 arethin, axially extending pieces of solid material. Shaft 42 is a cylinderof solid material. Inner portion 50 is a radially inward portion of tab46. Inner portion 50 includes a flat or straight cross-section shape.Middle portion 52 is a middle radial portion of tab 46. In this example,middle portion 52 includes a curved cross-section shape. Outer portion54 is an outward radial portion of tab 46. Outer portion 54 includes aflat or straight cross-section shape.

Here, support members 44 are shown as being integrally formed with andextending radially from shaft 42 of central spar 16. Tabs 46 areconnected to a radially outer surface of shaft 42. Tabs 46 areintegrally formed with shaft 42 via layer-by-layer additivemanufacturing. In this example, radially outer ends of tabs 46 areconnected to and integrally formed with heat exchanger core 22 (seee.g., FIG. 2 ). Shaft 42 is disposed coaxial with centerline axis A_(CL)and is integrally formed with inner portions 44 of tabs 46. Innerportion 50 is connected to and disposed between shaft 42 and middleportion 52 on tab 46. Middle portion 52 is connected to and disposedbetween inner portion 44 and outer portion 54. Outer portion 54 isconnected to middle portion 52 and is disposed on a radially outward endof tab 46.

Tabs 46 of support member 44 bend and flex as central spar 16 expandsand contracts due to increases and decreases in an amount of thermalenergy transferred to or away from central spar 16. Tabs 46 also bendand flex in response to vibrations of either heat exchanger 10 or themounting surface to which mounting arms 18A and 18B (shown in FIG. 3 )are mounted to. For example, tabs 46 can bend through middle portion 52due to the curved cross-sectional shape of middle portion 52. Shaft 42provides structural support to tabs 46 and to mounting arm 18A. Ascentral spar 16 absorbs thermal energy, shaft 42 expands axially andradially.

Inner portion 50 attaches tab 46 to shaft 42 of central spar 16. Thecurved cross-section shape of middle portion 52 acts as a flexiblemember to allow tab 46 to bend and flex as thermal expansion andvibrational loads are applied to both central spar 16 from heatexchanger 10 and from mounting arms 18A and 18B. Outer portion 54attaches to heat exchanger core 22 and attaches heat exchanger core 22to tab 46.

Support members 44 of tabs 46 provide a stiff enough connection betweenheat exchanger core 22 and central spar 16 to support vibrational loadswhile also providing enough flexibility in both the axial and radialdirections to allow for thermal expansion of body 12 (see e.g., FIG. 1 )without placing critical amounts of stress or strain on the mountinglocations of heat exchanger 10.

FIG. 5 is a supplementary cross-section view of heat exchanger 10 andshows body 12, exterior skin 14, central spar 16, mounting arms 18,external mount 20, heat exchanger core 22, external mounting surfaces24, connection region 26, first header 56 (with first annulus 58, firstradially inward sidewall 60, first radially outward sidewall 62, firstconvergent point 64, and drain port 66), second header 68 (with secondannulus 70, second radially inward sidewall 72, second radially outwardsidewall 74, second convergent point 76, and vent port 78), andcenterline axis A_(CL). In FIG. 5 , central spar 16, mounting arms 18,external mount 20, external mounting surfaces 24, and connection region26 are omitted for clarity.

First header 56 and second header 68 are hollow, curved portions ofsolid material. In this example, first header 56 and second headerinclude shapes of a half ring torus. First annulus 58 and second annulus72 are hollow, annular shaped components. First radially inward sidewall60, first radially outward sidewall 62, second radially inward sidewall72, and second radially outward sidewall 74 are angled, partially curvedwalls of solid material. First convergent point 64 and second convergentpoint 76 are angled, connection points. Drain port 66 and vent port 78are outlet orifices.

First header 56 is a part of body 12 and is located on a first axial endof body 12. In this example, first header 56 is shown on gravitationalbottom G_(B) (e.g., on the downward end as shown in FIG. 5 ) of body 12.First header 56 is in fluid communication with heat exchanger core 22.First annulus 58 is integrally formed with and connected to agravitational bottom of first header 56. First radially inward sidewall60 is integrally formed with and connected to a portion of exterior skin14 along first header 56 and to first radially outward sidewall 62.First radially outward sidewall 62 is integrally formed with andconnected to another portion of exterior skin 14 along first header 56and to first radially inward sidewall 60. First radially outwardsidewall 62 connects to first radially inward sidewall 60 to form firstconvergent point 64. First convergent point 64 extends around acircumference of first annulus 58. Drain port 66 is disposed in agravitational bottom of first annulus 58 at first convergent point. Inthis example, a series of drain ports 66 are disposed in and extendaround a circumference of first annulus 58 along first convergent point64.

Second header 68 is a part of body 12 and is located on a first axialend of body 12. In this example, second header 68 is shown ongravitational top G_(T) (e.g., on the upward end as shown in FIG. 5 ) ofbody 12. Second header 68 is in fluid communication with heat exchangercore 22. Second annulus 70 is integrally formed with and connected to agravitational top of second header 68. Second radially inward sidewall72 is integrally formed with and connected to a portion of exterior skin14 along second header 68 and to second radially outward sidewall 74.Second radially outward sidewall 74 is integrally formed with andconnected to another portion of exterior skin 14 along second header 68and to second radially inward sidewall 72. Second radially outwardsidewall 74 connects to second radially inward sidewall 72 to formsecond convergent point 76.

A direction of gravity G is shown in FIG. 5 , as well as planes P₁ andplane P₂. Planes P₁ and P₂ are oriented perpendicular to gravity G.First radially inward sidewall 60 intersects plane P₁ to form firstinward angle θ_(1I). In this example, first inward angle θ_(1I) isgreater than or equal to 40°. First radially outward sidewall 62intersects plane P₁ to form first outward angle θ_(1O). In this example,first outward angle θ_(1O) is greater than or equal to 40°. Secondradially inward sidewall 72 intersects plane P₂ to form second inwardangle θ_(2I). In this example, second inward angle θ_(2I) is greaterthan or equal to 40°. Second radially outward sidewall 74 intersectsplane P₂ to form second outward angle θ_(2O). In this example, secondoutward angle θ_(2O) is greater than or equal to 40°. Second convergentpoint 76 extends around a circumference of second annulus 70. Vent port78 is disposed in a gravitational top of second annulus 70 at firstconvergent point. In this example, a series of vent ports 78 aredisposed in and extends around a circumference of second annulus 70along second convergent point 76.

During operation of heat exchanger 10, first header 56 and second header68 contain and direct fluids into or out of heat exchanger core 22.First annulus 58 provides a cavity into which excess powder from theadditive manufacturing build process can flow into upon completion ofadditively manufacturing heat exchanger 10. First radially inwardsidewall 60 and first radially outward sidewall 62 direct excess powderfrom the additive manufacturing build process in a downward directiontowards first convergent point 64. Drain ports 66 along first convergentpoint 64 allow collected powder to drain or empty out of first annulus58 during powder removal post-processing steps of the additivemanufacturing build process.

Second annulus 70 provides a cavity into which air pressure can flowinto during post-processing (e.g., cleaning) steps during the additivelymanufacturing build process of heat exchanger 10. Second radially inwardsidewall 72 and second radially outward sidewall 74 direct air drawnfrom body 12 during a cleaning step of heat exchanger 10 out of body 12and to second convergent point 76. Vent port 78 at second convergentpoint 76 allows air pressure to be released from heat exchanger 10during powder removal post-processing steps of the additivemanufacturing build process.

In one example, a method of building heat exchanger 10 includes formingheat exchanger 10 with layer-by-layer additive manufacturing. Here, abuild-direction of heat exchanger 10 is bottom-to-top, shown as in theopposite direction to gravity G in FIG. 5 . Forming heat exchanger 10includes forming first annulus 58. First annulus 58 is formed to includea conical cross-section shape and to include drain port 66 disposedalong a gravitational bottom of first annulus 58. First annulus 58includes first radially inward sidewall 60 and first radially outwardsidewall 62, where first radially inward sidewall 60 and first radiallyoutward sidewall 62 connect together to form first convergent point 64.An angle between first radially inward sidewall 60 and first radiallyoutward sidewall 62 at first convergent point 64 is acute. Firstradially inward sidewall 60 is formed such that angle θ_(1I) betweenfirst radially inward sidewall 60 and plane P₁ that perpendicular to thedirection of gravity is greater than or equal to 40°. First radiallyoutward sidewall 62 is formed such that an angle between first radiallyoutward sidewall 62 and plane P₁ that is perpendicular to the directionof gravity is greater than or equal to 40°. Body 12 of heat exchanger 10is formed such that body 12 is integrally connected to first annulus 58and such that first annulus 58 is disposed on a gravitational bottom ofbody 12. Heat exchanger core 22 is formed such that fins of heatexchanger core 22 are parallel with a direction of gravity.

Second annulus 70 that is integrally connected to a gravitational top ofbody 12 is formed and includes a conical cross-section shape. Secondannulus 70 is formed to include vent port 78 disposed on a gravitationaltop of second annulus 70. Second annulus 70 incudes second radiallyinward sidewall 72 and second radially outward sidewall 74, where secondradially inward sidewall 72 and second radially outward sidewall 74connect together to form second convergent point 76. An angle betweensecond radially inward sidewall 72 and second radially outward sidewall74 at second convergent point 76 is acute. Second radially inwardsidewall 72 is formed such that an angle between second radially inwardsidewall 72 and plane P₂ that is perpendicular to the direction ofgravity is greater than or equal to 40°. Second radially outwardsidewall 74 is formed such that an angle between second radially outwardsidewall 74 and plane P₂ that is perpendicular to the direction ofgravity is greater than or equal to 40°.

Residual powder is collected from body 12 in first annulus 58. Residualpowder is removed from heat exchanger 10 and air is vented from body 12though vent port 78 in second annulus 70. Removing residual powder fromheat exchanger 10 includes applying at least one of ultrasonicvibration, low-frequency shock, and a fluid wash to body 12. Inparticular, residual powder is removed from body 12 through drain port66 in first annulus 58. Air is vented from body 12 though vent port 78in second annulus 70.

Orienting the build-direction of heat exchanger 10 opposite to gravityallows for a single-axis orientation set for heat exchanger 10 based onits shape and internal geometry. This orientation enables all internalpassages to be formed parallel with the gravitational vector (e.g.,gravity G) to allow flow of residual powder in a single direction. Here,because first header 56 and second header 68 are integrally formedtogether with body 12, the use of vent ports 78 is enabled which breaksany powder removal vacuums created during powder removal process steps.Likewise, the incorporation of conformal, conical first header 56 andradial configuration of heat exchanger core 22 allows for drain port 66to be located in body 12 at the lowest point of the orientation at whichresidual powder will be removed.

Some of the benefits enabled by this configuration and build process ofheat exchanger 10 include improved powder removal, reduced weight,improved build speed, and improved performance of heat exchanger 10.

FIG. 6A is a perspective isolation side-by-side view of first fluidcircuit 80 of heat exchanger core 22 and shows first set of fins 82,first inlet header 84, and first outlet header 86.

First fluid circuit 80 is a circuit for transporting a fluid throughheat exchanger core 22. First set of fins 82 is a group of sheets ofsolid material, with open channels passing through the sheets. Firstinlet header 84 and first outlet header 86 are circular/annular shapedpieces of material that form hollow annuluses therein. First fluidcircuit 80 forms a part of heat exchanger core 22 disposed in body 12 ofheat exchanger 10. The fins of first set of fins 82 extend radiallyoutward and are coaxial with each other and with centerline axis A_(CL).In this example, first set of fins 82 includes a helical shape orconfiguration. First inlet header 84 is fluidly connected to and isdisposed on an upstream end of first set of fins 82. First outlet header86 is fluidly connected to and is disposed on a downstream end of firstset of fins 82. First inlet header 84 and first outlet header 86 eachform a hollow annulus with a centerpoint that is coaxial with centerlineaxis A_(CL).

First fluid circuit 80 acts as a conduit through which a first fluidpasses in order to facilitate the transfer of thermal energy between thefirst fluid and one or more other fluids passing through heat exchangercore 22 during operation of heat exchanger 10. In this example, firstfluid circuit 80 receives and guides a first fluid that is air. Firstset of fins 82 guide the first fluid through heat exchanger core 22. Viaconduction, first set of fins 82 transfers thermal energy between thefirst fluid and a second fluid passing through heat exchanger core 22.First inlet header 84 controls and directs a flow of the first fluidfrom an external piping system upstream of heat exchanger core 22 intoheat exchanging core 22. First outlet header 86 controls and directs theflow of the first fluid from heat exchanging core 22 another externalpiping system downstream of heat exchanger core 22.

FIG. 6B is a perspective isolation side-by-side view of second fluidcircuit 88 of heat exchanger core 22 and shows second set of fins 90,second inlet header 92, and second outlet header 94.

Second fluid circuit 88 is a circuit for transporting a fluid throughheat exchanger core 22. Second set of fins 90 is a group of sheets ofsolid material, with open channels passing through the sheets. Secondinlet header 92 and second outlet header 94 are circular/annular shapedpieces of material that form hollow annuluses therein. Second fluidcircuit 88 forms a part of heat exchanger core 22 disposed in body 12 ofheat exchanger 10. The fins of second set of fins 90 extend radiallyoutward and are coaxial with each other and with centerline axis A_(CL).In this example, second set of fins 90 includes a helical shape orconfiguration. Second inlet header 92 is fluidly connected to and isdisposed on an upstream end of second set of fins 90. Second outletheader 94 is fluidly connected to and is disposed on a downstream end ofsecond set of fins 90. Second inlet header 92 and second outlet header94 each form a hollow annulus with a centerpoint that is coaxial withcenterline axis A_(CL).

Second fluid circuit 88 acts as a conduit through which a second fluidpasses in order to facilitate the transfer of thermal energy between thesecond fluid and one or more other fluids passing through heat exchangercore 22 during operation of heat exchanger 10. In this example, secondfluid circuit 88 receives and guides a second fluid that is fuel. Secondset of fins 90 guide the first fluid through heat exchanger core 22. Viaconduction, second set of fins 90 transfers thermal energy between thesecond fluid and a first fluid passing through heat exchanger core 22.Second inlet header 92 controls and directs a flow of the first fluidfrom an external piping system upstream of heat exchanger core 22 intoheat exchanging core 22. Second outlet header 94 controls and directsthe flow of the first fluid from heat exchanging core 22 anotherexternal piping system downstream of heat exchanger core 22.

FIG. 6C is a perspective isolation side-by-side view of first and secondfluid circuits 80 and 88 nested together and shows first fluid circuit80 (with first set of fins 82, first inlet header 84, and first outletheader 86), second fluid circuit 88 (with second set of fins 90, secondinlet header 92, and second outlet header 94), and third fluid circuit96 (with third inlet header 98 and third outlet header 100).

Third fluid circuit 96 is a third circuit for transporting a fluidthrough heat exchanger core 22. Third inlet header 98 and third outletheader 100 are circular/annular shaped pieces of material that formhollow annuluses therein. Chamber 102 is a pipe or hollow cylinder.Third inlet header 98 is fluidly connected to and is disposed on anupstream end of chamber 102. Third outlet header 100 is fluidlyconnected to and is disposed on a downstream end of chamber 102. Each ofthe first, second, and third inlet headers 84, 92, and 98 are shown asbeing disposed coaxial with each other and with centerline axis A_(CL).First inlet header 84 is the radially inner most header of the first,second, and third inlet headers 84, 92, and 98. Third inlet header 98 isdisposed radially outward from first inlet header 84 and is disposedradially inward from second inlet header 92. Second inlet header 92 isdisposed radially outward from first inlet header 84 and from thirdinlet header 98.

In this example, the annular and circular shape of second inlet header92 conforms to or matches the circular shapes of first inlet header 84and of third inlet header 98. Likewise, the annular and circular shapeof third inlet header 98 conforms to or matches the circular shape offirst inlet header 84 and second inlet header 92. Here, first set offins 82 and second set of fins 90 are shown as being nested with eachother. For example, first set of fins 82 and second set of fins 90 aredisposed such that the fins of each form an alternating pattern in acircumferential direction. Each fin of first set of fins 82 ispositioned between two fins of second set of fins 90. Likewise, each finof second set of fins 90 is positioned between two fins of first set offins 82. Each fin of both first and second sets of fins 82 and 90conform, or match, each other's shape. Chamber 102 is disposed along acenter of heat exchanger core 22 and is fluidly connected to both thirdinlet header 98 and third outlet header 100. Chamber 102 is disposedcoaxial with centerline axis A_(CL).

Third fluid circuit 96 acts as a conduit through which a second fluidpasses in order to facilitate the transfer of thermal energy between athird fluid and one or more other fluids passing through heat exchangercore 22 during operation of heat exchanger 10. Third inlet header 98controls and directs a flow of the first fluid from an external pipingsystem upstream of heat exchanger core 22 into heat exchanging core 22.Third outlet header 100 controls and directs the flow of the first fluidfrom heat exchanging core 22 to another external piping systemdownstream of heat exchanger core 22. Chamber 102 guides the third fluidthrough heat exchanger core 22. Chamber 102 acts as a pass-throughchamber through which additional fluid is fed. In one non-limitingembodiment, third fluid circuit can be used as a back-up circuit to beused in the instance that one or both of first fluid circuit 80 and/orsecond fluid circuit 88 break-down, leak, or fail.

FIG. 6D is a perspective isolation side-by-side view of first, second,and third fluid circuits 80, 88, and 96 combined together andadditionally shows barrier layer 104 disposed on portions of heatexchanger core 22.

Barrier layer 104 is a thin layer or sheet of solid material. In thisexample, barrier layer 104 surrounds all surfaces of second fluidcircuit including second set of fins 90, second inlet header 92, andsecond outlet header 94. Barrier layer 104 also surrounds the surfacesof third fluid circuit including third inlet header 98, third outletheader 100, and chamber 102. Each of first fluid circuit 80, secondfluid circuit 88, third fluid circuit 96, and barrier layer 104 areintegrally formed with each other via layer-by-layer additivemanufacturing. Barrier layer 104 prevents leakage of the first fluid,second fluid, and/or third fluid between first fluid circuit 80, secondfluid circuit 88, and/or third fluid circuit 96. Barrier layer 104 addsa redundant safety feature of heat exchanger core 22 that prevents fluidtransfer between any of first fluid circuit 80, second fluid circuit 88,and/or third circuit 96.

Here, first fluid circuit 80, second fluid circuit 88, third fluidcircuit 96, and barrier layer 104 are shown as conforming around eachother and with a cylindrically packaged radial core (e.g., heatexchanger core 22). With heat exchanger 10, the use of additivemanufacturing enables the conforming shapes of first fluid circuit 80,second fluid circuit 88, third fluid circuit 96, and barrier layer 104that would otherwise be extremely difficult to manufacture usingnon-additive manufacturing techniques. This conformal aspect of theheaders of heat exchanger 10 enables the features of a round/curvedexterior, conformal fluid channels, varying of fluid inlet and exitgeometries, varying of channel inlet shape, varying of inlet finprofiles, variable fin geometry integral header and core (manufacturedas one piece), integrated plumbing in header for other systems such asbypass lines, sensors, or wire ways through center of core, enhancedbuildability/powder removal, and the ability to integrate conformalbarrier passages.

These features provide the benefits of enhanced pressure and temperaturecapability vs. weight, increased thermal transient capability, improvedtotal heat exchanger volume vs. heat transfer, improved total heatexchanger volume vs. pressure drop, and improved packaging and systemintegration through/around other components. In particular, the annularor circular shapes of first, second, and this inlet headers 84, 92, and98 as well as first, second, and third outlet headers 86, 94, and 100allow increased temperature and pressure loading capability versusweight (e.g., square corners are eliminated) are removed. Additionally,the shapes of the external header surfaces are conformal to the fluidflows thus allowing incorporation of additional heat transfer surfacearea in inlet headers 84, 92, and 98 as well as first, second, and thirdoutlet headers 86, 94, and 100 and an increase in overall thermalperformance vs. a weight-to-volume ratio of heat exchanger 10.

FIG. 7A is a cross-section view of first inlet header 84 and shows inlet106, sidewall 108, and guide fins 110.

Inlet 106 is an inlet port of first inlet header 84. Sidewall 108 is anexterior wall of first inlet header 84. Guide fins 110 are thin sheetsof solid material. In this example, guide fins 110 include approximatelythree different lengths. Inlet 106 extends axially and radially from anupstream (e.g., left as shown in FIG. 7A) end of first inlet header 84.Sidewall 108 extends around an exterior of first inlet header 84. Guidefins 110 are disposed inside of sidewall 108. Guide fins 110 extend andcurl towards inlet 106. In this example, each portion of guide fins 110retains a uniform radius from centerline axis A_(CL) as each of guidefins 110 is revolved about centerline axis A_(CL). Also in this example,guide fins 110 are integrally formed with and connected to heatexchanger core 22.

Inlet 106 guides and transports a flow of the first fluid into firstinlet header 84. Sidewall 108 contain the flow of first fluid withinfirst inlet header 84. Guide fins 110 direct various portions of theflow of first fluid from inlet 106 to different radial sections of firstinlet header 84. For example, a downstream end (e.g., right end as shownin FIG. 7A) of first inlet header 84 is connected to and formed with anupstream end of heat exchanger core 22. As the first fluid istransferred from first inlet header 84, guide fins 110 direct the firstfluid to various radial sections of heat exchanger core 22. Guide fins110 direct the first fluid to various radial sections of first inletheader 84 with the curved shape of guide fins 110. As the flow of firstfluid comes into contact with upstream ends of guide fins 110, guidefins 110 deflect and angle the flow of the first fluid into a radiallyoutward direction.

In addition to directing the flow of the first fluid to all radialsections of heat exchanger core 22, guide fins 110 are arranged tomaximize thermal fluid performance and minimize structural stresses offirst inlet header 84. With respect to the build process of heatexchanger 10, guide fins 110 help to guide residual powder towards inlet106 as the residual powder is removed from heat exchanger core 22. Firstinlet header 84 with guide fins 110 creates fluid channels between eachof guide fins 110 that are conformal to each other allowing foroptimized heat transfer vs. volume and weight. In addition, the fluidchannels between each of guide fins 110 incorporates secondary surfacearea in the form of guide fins 110 that both direct the flow to maximizefluid distribution entering heat exchanger core 22 as well as heattransfer in first inlet header 84. Likewise, the conformal design ofguide fins 110 also allows for integration of barrier layers betweenfluids when required.

FIG. 7B is a cross-section view of second inlet header 92 and showsinlet 112, sidewall 114, and guide fins 116.

Inlet 112 is an inlet port of second inlet header 92. Sidewall 114 is anexterior wall of second inlet header 92. Guide fins 116 are thin sheetsof solid material. Inlet 112 extends axially from an upstream (e.g.,left as shown in FIG. 7A) end of second inlet header 92. Sidewall 114extends around an exterior of second inlet header 92. Guide fins 116 aredisposed inside of sidewall 114. In this example, a curved shape ofguide fines 110 matches or conforms to the curvature of sidewall 114. Inthis example, each portion of guide fins 116 retains a uniform radiusfrom a center of inlet 112 as each of guide fins 116 is revolved aboutcenter of inlet 112 Also in this example, guide fins 116 are integrallyformed with and connected to heat exchanger core 22.

Inlet 112 guides and transports a flow of the second fluid into secondinlet header 92. Sidewall 114 contain the flow of first fluid withinsecond inlet header 92. Guide fins 116 direct various portions of theflow of first fluid from inlet 112 to different radial sections ofsecond inlet header 92. For example, a downstream end (e.g., right endas shown in FIG. 7A) of second inlet header 92 is connected to andformed with an upstream end of heat exchanger core 22. As the secondfluid is transferred from second inlet header 92, guide fins 116 directthe second fluid to various radial sections of heat exchanger core 22.Guide fins 116 direct the second fluid to various radial sections ofsecond inlet header 92 with the curved shape of guide fins 116. As theflow of the second fluid comes into contact with upstream ends of guidefins 116, guide fins 116 deflect and angle the flow of the second fluidinto a radially outward direction.

In addition to directing the flow of the second fluid to all radialsections of heat exchanger core 22, guide fins 116 are arranged tomaximize thermal fluid performance and minimize structural stresses ofsecond inlet header 92. With respect to the build process of heatexchanger 10, guide fins 116 help to guide residual powder towards inlet112 as the residual powder is removed from heat exchanger core 22.

Second inlet header 92 with guide fins 116 creates fluid channelsbetween each of guide fins 116 that are conformal to each other allowingfor optimized heat transfer vs. volume and weight. In addition, thefluid channels between each of guide fins 116 incorporates secondarysurface area in the form of guide fins 116 that both direct the flow tomaximize fluid distribution entering heat exchanger core 22 as well asheat transfer in second inlet header 92. Likewise, the conformal designof guide fins 116 also allows for integration of barrier layers betweenfluids when required.

FIG. 8 is a supplementary cross-section view of a portion of heatexchanger core 22 and shows first set of channels 118 (each with widthW_(1C)), second set of channels 120 (each with width W_(2C)), firstradial region 122, second radial region 124, and third radial region126. FIG. 9 is a perspective isolated view of heat exchanger core 22 andshows first set of channels 118 (each with width W_(1C)), second set ofchannels 120 (each with width W_(2C)), first radial region 122, secondradial region 124, and third radial region 126. FIGS. 8 and 9 will bediscussed in tandem.

First set of channels 118 and second set of channels 120 are fluidicpassages. Each channel of first set of channels 118 includes a taperedshape that increases in width along a radially outward direction. Eachchannel of second set of channels 120 includes a tapered shape thatincreases in width along the radially outward direction. Width W_(1C) isa width of a channel of first set of channels 118. Here, width W ismeasured in a circumferential direction relative to centerline axisA_(CL). Width W_(2C) is a width of a channel of second set 124 ofchannels 118. Here, width W is measured in a circumferential directionrelative to centerline axis A_(CL). First radial region 122, secondradial region 124, and third radial region 126 are radially distinct andstep-wise sections of heat exchanger core 22. Each of First radialregion 122, second radial region 124, and third radial region 126include a plurality of first set of channels 118 and a plurality ofsecond set of channels.

The channels of first and second sets of channels 118 and 120 extendradially outward relative to axial centerline A_(CL). Channels of firstset of channels 118 is nested and interspersed between channels ofsecond set of channels 120. For example, in each of first radial region122, second radial region 124, and third radial region 126, there is analternating pattern of channels of first set of channels 118 andchannels of second set of channels 118 in a circumferential direction.Each channel of both first set of channels 118 and second set ofchannels 120 are defined by fins (see e.g., first set of fins 82 andsecond set of fins 90 in FIGS. 6A and 6B) that define an exteriorboundary for each channel (such fins have been omitted from FIG. 8 forclarity). The channels of first set of channels 118 are fluidly isolatedfrom the channels of second set of channels 120.

Width W_(1C) and width W_(1C) vary relative to a radial distance fromcenterline axis A_(CL) of heat exchanger core 22. In this example, widthW_(1C) and width W_(2C) both increase as a radial distance fromcenterline axis A_(CL) increases. First radial region 122 is disposedradially inward from second radial region 124. Second radial region 124is disposed radially between first radial region 122 and third radialregion 126. Third radial region 126 is disposed radially outward fromsecond radial region 124. In this example, first, second, and thirdradial regions 122, 124, and 16 extend axially for an entire length ofheat exchanger core 22.

First set of channels 118 transports the first fluid through heatexchanger core 22. As the first fluid flows through first set ofchannels 22 of heat exchanger core, thermal energy is transferred acrossthe fins defining the channels and into the second fluid flowing throughsecond set of channels 120.

With both of width W_(1C) and width W_(2C) both increasing as a radialdistance from centerline axis A_(CL) increases, a ratio of width W_(1C)to width W_(2C) is maintained across all radial distances fromcenterline axis A_(CL). For example, in each of first radial region 122,second radial region 124, and third radial region 126, the ratio ofwidth W_(1C) to width W_(2C) is approximately constant or uniformthroughout each of first radial region 122, second radial region 124,and third radial region 126. Width W_(1C) of each channel of first setof channels 118 at a first radial location from centerline axis A_(CL)is greater than width W_(2C) of each channel of second set of channels120 at the same radial location from centerline axis A_(CL).

In this example, a ratio of a cross-sectional area of a channel of firstset of channels 118 to a cross-sectional area of a channel of second setof channels 120 is uniform along a radial direction of heat exchangercore 22. This uniform ratio enables a more uniform transfer of thermalenergy across each of first, second, and third radial regions 122, 124,and 126 of heat exchanger core 22.

The round or curved exterior and the round or oval body of heatexchanger 10 allows for increased temperature and pressure loadingcapability. The variable geometry of the fins and the channels enablevariations in geometry that are parallel with the directions of fluidflow through heat exchanger core 22. Likewise, the geometries of thefins and channels can be varied and optimized for thermal energytransfer as fluid flow temperature and fluid density change down alength of heat exchanger core 22. In heat exchanger core 22, fin andchannel geometries are varied with flow direction and are optimized forcompliance under rapid thermal transients at fluid inlets (e.g., inlets106 and 112). Additionally, stiffnesses of the fins (e.g.,thickness/shape/spacing) can be varied from a center of heat exchanger10 outwardly to provide compliance in order to allow for expansion anddistortion during pressure and temperature transients. Furthermore, theintegral one piece configuration of heat exchanger core 22 eliminateschallenges with bonding multiple preformed shapes together.

Discussion of Possible Embodiments

A heat exchanger includes a first set of fins, a second set of fins, andan exterior wall. The first set of fins extend radially and are coaxialwith each other. The first set of fins forms a first set of channels.The second set of fins extend radially and are coaxial with each other.The second set of fins forms a second set of channels. Channels of thefirst and second sets of channels are disposed in an alternating patternin a circumferential direction of the heat exchanger. The first andsecond sets of fins are integrally formed together. A cross-sectionalwidth of a channel of at least one of the first set of channels and thesecond set of channels increases as a radial distance from a centerlineaxis of the heat exchanger increases.

The heat exchanger of the preceding paragraph can optionally include,additionally and/or alternatively, any one or more of the followingfeatures, configurations and/or additional components.

The first and second sets of channels can have a first radial region,and/or wherein each channel of the first set of channels can comprise atapered shape that increases in width along a radially outwarddirection, each channel of the second set of channels can comprise atapered shape that increases in width along the radially outwarddirection, and/or a ratio between a width of a channel of the first setof channels and a width of a channel of the second set of channels canremain approximately constant across the first radial region.

The cross-sectional width of each channel of the first set of channelsat a first radial location from the axial centerline of the heatexchanger can be greater than the width of each channel of the secondset of channels at the same radial location from the axial centerline ofthe heat exchanger.

Each fin of the first set of fins can include a helical shape, and/oreach fin of the second set of fins can match the helical shape of eachfin of the first set of fins.

The channels of the first and second sets of channels can extendradially outward relative to the axial centerline of the heat exchanger.

A ratio of a cross-sectional area of a channel of the first set ofchannels to a cross-sectional area of a channel of the second set ofchannels can be uniform along a radial direction of the heat exchanger.

The first and second sets of fins can be integrally formed with theexterior wall via layer-by-layer additive manufacturing.

The first and second sets of channels can be fluidly separated from oneanother and can be configured to transfer heat from a first fluidflowing through the first set of channels to a second fluid flowingthrough the second set of channels.

A method of manufacturing a heat exchanger can include forming a firstand a second set of fins via layer-by-layer additive manufacturing. Thefirst set of fins can extend radially, can be coaxial with each other,and form a first set of channels. A second set of fins extends radiallyand can be coaxial with each other. The second set of fins forms asecond set of channels. The channels of the first and second sets ofchannels can be disposed in an alternating pattern in a circumferentialdirection. The first and second sets of fins can be integrally formedtogether. A cross-sectional width of a channel of at least one of thefirst set of channels and the second set of channels increases as aradial distance from a centerline axis of the heat exchanger increases.A curved exterior wall can be formed with layer-by-layer additivemanufacturing and such that the curved exterior wall can be integrallyformed to the first and second sets of fins. The first and second setsof fins can be contained within the exterior wall.

The method of the preceding paragraph can optionally include,additionally and/or alternatively, any one or more of the followingsteps, features, configurations and/or additional components.

Each channel of the first set of channels can be formed withlayer-by-layer additive manufacturing to comprise a tapered shape thatincreases in width along a radially outward direction; each channel ofthe second set of channels can be formed with layer-by-layer additivemanufacturing to comprise a tapered shape that increases in width alongthe radially outward direction; and/or wherein a ratio between a widthof a channel of the first set of channels and a width of a channel ofthe second set of channels can remain approximately constant across afirst radial region of the first and second sets of channels.

The cross-sectional width of each channel of the first set of channelsat a first radial location from the axial centerline of the heatexchanger can be greater than the width of each channel of the secondset of channels at the same radial location from the axial centerline ofthe heat exchanger.

Each fin of the first set of fins can include a helical shape, and/oreach fin of the second set of fins can match the helical shape of eachfin of the first set of fins.

The channels of the first and second sets of channels can extendradially outward relative to the axial centerline of the heat exchanger.

A ratio of a cross-sectional area of a channel of the first set ofchannels to a cross-sectional area of a channel of the second set ofchannels can be uniform along a radial direction of the heat exchanger.

While the invention has been described with reference to an exemplaryembodiment(s), it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed, but that theinvention will include all embodiments falling within the scope of theappended claims.

The invention claimed is:
 1. A heat exchanger comprising: a first set offins that extend radially and that are coaxial with each other, whereinthe first set of fins forms a first set of channels; a second set offins that extend radially and that are coaxial with each other, wherein:the second set of fins and the first set of fins form an alternatingpattern in a circumferential direction such that each fin of the firstset of fins is positioned between two fins of the second set of fins andeach fin of the second set of fins is positioned between two fins of thefirst set of fins; and the second set of fins forms a second set ofchannels, wherein channels of the first and second sets of channels aredisposed in an alternating pattern in a circumferential direction,wherein the first and second sets of fins are integrally formedtogether, and wherein a cross-sectional width of a channel in thecircumferential direction of at least one of the first set of channelsand the second set of channels increases as a radial distance from acenterline axis of the heat exchanger increases; a curved exterior wall,wherein the first and second sets of fins are contained within theexterior wall; a first inlet header and a first outlet header, whereinthe first inlet header is fluidly connected to and disposed on anupstream end of the first set of fins, and wherein the first outletheader is fluidly connected to and disposed on a downstream end of thefirst set of fins; a second inlet header and a second outlet header,wherein the second inlet header is fluidly connected to and disposed onan upstream end of the second set of fins, and wherein the second outletheader is fluidly connected to and disposed on a downstream end of thesecond set of fins; and a third inlet header and a third outlet header,wherein the third inlet header is fluidly connected to and disposed onan upstream end of a chamber, and wherein the third outlet header isfluidly connected to and disposed on a downstream end of the chamber. 2.The heat exchanger of claim 1, wherein the first and second sets ofchannels have a first radial region, and wherein: each channel of thefirst set of channels comprises a tapered shape that increases in widthalong a radially outward direction; each channel of the second set ofchannels comprises a tapered shape that increases in width along theradially outward direction; and a ratio between a width of a channel ofthe first set of channels and a width of a channel of the second set ofchannels remains approximately constant across the first radial region.3. The heat exchanger of claim 1, wherein the cross-sectional width ofeach channel of the first set of channels at a first radial locationfrom the axial centerline of the heat exchanger is greater than thewidth of each channel of the second set of channels at the same radiallocation from the axial centerline of the heat exchanger.
 4. The heatexchanger of claim 1, wherein each fin of the first set of fins includesa helical shape; and wherein each fin of the second set of fins matchesthe helical shape of each fin of the first set of fins.
 5. The heatexchanger of claim 1, wherein the channels of the first and second setsof channels extend radially outward relative to the axial centerline ofthe heat exchanger.
 6. The heat exchanger of claim 1, wherein a ratio ofa cross-sectional area of a channel of the first set of channels to across-sectional area of a channel of the second set of channels,measured at a same radial distance from the axial centerline, is uniformat all radial distances from the axial centerline along the radialdirection of the heat exchanger.
 7. The heat exchanger of claim 1,wherein the first and second sets of fins are integrally formed with theexterior wall via layer-by-layer additive manufacturing.
 8. The heatexchanger of claim 1, wherein the first and second sets of channels arefluidly separated from one another and are configured to transfer heatfrom a first fluid flowing through the first set of channels to a secondfluid flowing through the second set of channels.
 9. A method ofmanufacturing a heat exchanger, the method comprising: forming a firstand a second set of fins, wherein: the first set of fins that extendradially and that are coaxial with each other, wherein the first set offins forms a first set of channels; a second set of fins that extendradially and that are coaxial with each other, wherein: the second setof fins and the first set of fins form an alternating pattern in acircumferential direction such that each fin of the first set of fins ispositioned between two fins of the second set of fins and each fin ofthe second set of fins is positioned between two fins of the first setof fins; and the second set of fins forms a second set of channels,wherein channels of the first and second sets of channels are disposedin an alternating pattern in a circumferential direction, wherein thefirst and second sets of fins are integrally formed together, andwherein a cross-sectional width of a channel of at least one of thefirst set of channels and the second set of channels increases as aradial distance from a centerline axis of the heat exchanger increases;and forming a curved exterior wall, wherein the curved exterior wall isintegrally formed to the first and second sets of fins, wherein thefirst and second sets of fins are contained within the exterior wall;forming a first inlet header and a first outlet header, wherein thefirst inlet header is fluidly connected to and disposed on an upstreamend of the first set of fins, and wherein the first outlet header isfluidly connected to and disposed on a downstream end of the first setof fins; forming a second inlet header and a second outlet header,wherein the second inlet header is fluidly connected to and disposed onan upstream end of the second set of fins, and wherein the second outletheader is fluidly connected to and disposed on a downstream end of thesecond set of fins; and a third inlet header and a third outlet header,wherein the third inlet header is fluidly connected to and disposed onan upstream end of a chamber, and wherein the third outlet header isfluidly connected to and disposed on a downstream end of the chamber.10. The method of claim 9, further comprising: forming each channel ofthe first set of channels to comprise a tapered shape that increases inwidth along a radially outward direction; forming each channel of thesecond set of channels to comprise a tapered shape that increases inwidth along the radially outward direction; and wherein a ratio betweena width of a channel of the first set of channels and a width of achannel of the second set of channels remains approximately constantacross a first radial region of the first and second sets of channels.11. The method of claim 9, wherein the cross-sectional width of eachchannel of the first set of channels at a first radial location from theaxial centerline of the heat exchanger is greater than the width of eachchannel of the second set of channels at the same radial location fromthe axial centerline of the heat exchanger.
 12. The method of claim 9,wherein each fin of the first set of fins includes a helical shape; andwherein each fin of the second set of fins matches the helical shape ofeach fin of the first set of fins.
 13. The method of claim 9, whereinthe channels of the first and second sets of channels extend radiallyoutward relative to the axial centerline of the heat exchanger.
 14. Themethod of claim 9, wherein a ratio of a cross-sectional area of achannel of the first set of channels to a cross-sectional area of achannel of the second set of channels, measured at a same radialdistance from the axial centerline, is uniform at all radial distancesfrom the axial centerline along the radial direction of the heatexchanger.